In ancient Athens, the social structure was hierarchical. At the bottom of this structure were enslaved people. They had no legal rights and were considered property, often working in households, farms, and various trades.
Women and children, while they had limited rights compared to free men, were not at the very bottom of the social hierarchy. Women were generally restricted to certain roles and had fewer rights than men, but they were still considered citizens if they were born to Athenian parents. Children, particularly free-born boys, had the potential to rise in social status as they grew up and were educated.
In summary, among the groups you listed—enslaved people, women, and children—enslaved people were at the bottom of the social structure in Athens.